| 1. |
- Blum, Kristin M., et al.
(författare)
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Removal of 30 active pharmaceutical ingredients in surface water under long-term artificial UV irradiation
- 2017
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 176, s. 175-182
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the i) kinetics, and ii) proportion of photolysis of 30 relatively stable active pharmaceutical ingredients (APIs) during artificial UV irradiation for 28 d in ammonium acetate buffer, filtered and unfiltered river water. Buffer was included to control removal kinetics under stable pH conditions and without particulate matter. Dark controls were used to determine removal due to other processes than photolysis and calculate the proportion of photolysis of the total removal. The removal of each API in each matrix was determined using online solid phase extraction/liquid chromatography tandem mass spectrometry (online SPE/LC-MS/MS). Most APIs transformed during the 28 d of UV irradiation and the dark controls showed that photolysis was the major removal process for the majority of the APIs studied. The half-lives ranged from 6 h (amitriptyline) in unfiltered river water to 884 h (37 d, carbamazepine) in buffer. In unfiltered river water, the proportion of APIs with short half-lives (<48 h) was much higher (29%) than in the other matrices (4%), probably due to additional organic carbon, which could have promoted indirect photolysis. Furthermore, two APIs, memantine and fluconazole, were stable in all three matrices, while alprazolam was stable in buffer and unfiltered river water and four additional APIs were stable in buffer. Considering the relatively long-term UV-exposure, this study enabled the investigation of environmentally relevant half-lives in natural waters. Many APIs showed high persistence, which is environmentally concerning and emphasizes the importance of further studies on their environmental fate and effects.
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| 2. |
- Levinsson, Henrik, et al.
(författare)
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Suicidal behaviour in over-indebted individuals : a cross-sectional study in Sweden
- 2023
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Ingår i: Nordic Journal of Psychiatry. - : Taylor & Francis. - 0803-9488 .- 1502-4725. ; 77:7, s. 669-675
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Associations between debt and suicidal behaviour have been identified, but the research is sparse. Thus, more research is needed to understand the association between economic vulnerability and suicide. The study aimed to generate further knowledge about over-indebted individuals who have attempted suicide at least once. Method: Participants were a Swedish sample comprising 641 over-indebted individuals. The inclusion criteria were that the participants should be indebted and have been subjected to debt collection measures and/or seizure orders by the Swedish Enforcement Authority. Participants answered questionnaires regarding socio-demographic variables, debt size, history of suicide attempt, critical life events, and social contacts, and filled the Hospital Anxiety and Depression Scale (HADS). In the statistical analyses, Chi2 test for independence and t-test was used, and binary logistic regression to adjust for the confounding effects of the variables on each other. Results: The analysis revealed that nearly one in five (19.3%, N = 123) had attempted suicide at least once. A larger part of the respondents who had a history of suicide attempts reported that they were living alone (OR 2.30 (95% CI 1.34–3.89, p =.002). Many of those living alone were women (χ2 (1, n = 121) = 4.88, p = 0.03, ɸ = 0.22). Conclusions: The results of the current study point to the fact that economic vulnerability is an important psychosocial aspect to take into serious consideration concerning mental health and suicide prevention. Longitudinal research is needed to explain, predict and prevent suicide due to over-indebtedness.
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| 3. |
- Starrsjö, Sara, et al.
(författare)
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Assessment of Q(OP)D(PO) bleachability of softwood kraft pulp
- 2021
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Ingår i: Nordic Pulp & Paper Research Journal. - : Walter de Gruyter GmbH. - 0283-2631 .- 2000-0669. ; 36:4, s. 582-593
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Tidskriftsartikel (refereegranskat)abstract
- Bleachability is evaluated as how easily a pulp sample is bleached and it depends on the structure of residual lignin and carbohydrates. Also, the bleachability varies depending on the bleaching sequence. ECF light sequences have been improved significantly in the recent years. However, we still don't fully understand how ECF light bleach plants are optimally run. This work studies the bleachability of softwood kraft pulp in an ECF light bleaching sequence, (OO)Q(OP)D(PO). Three pulp samples with brown stock kappa number 27, 32 and 35 were bleached and studied for residual lignin, hexenuronic acid and carbohydrate content. It was found that in the bleaching stages that are highly delignifying, it is beneficial with a higher kappa number for the delignifying bleachability. However, in the bleaching stages where the objective is brightness increase, the brightness gain bleachability is improved by a lower kappa number. We also intended to determine which of the three samples had the best suited kappa number for this particular bleaching sequence. According to our results, the bleaching was most effective with kappa number around 32. Although an even higher kappa number resulted in higher yield after cooking, it seemed that this bleaching sequence cannot preserve the yield gain.
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| 4. |
- Starrsjö, Sara
(författare)
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On the Process Development of an ECF Light Bleaching Sequence for the Production of High Quality Softwood Kraft Pulp and Low AOX Formation
- 2021
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this work is to contribute to the process development of the ECF light bleaching sequence Q(OP)D(PO) by providing a better understanding of the bleaching of softwood kraft pulp. There are few published studies on this type of sequence, and more knowledge is needed on how to reduce environmental impact, improve cost-effectiveness and ensure a high pulp quality.Firstly, this research showed that using a pH buffer to stabilize the pH at a near-neutral level during bleaching with chlorine dioxide can lower the formation of adsorbable organically bound halogens (AOX) without altering the bleaching efficiency. A near-neutral pH decreases the formation of strongly chlorinating species so that the AOX content in the bleaching effluents is reduced by up to 30%. The increased pH in the near-neutral pH D stage compared with the reference lowered the chlorine dioxide consumption, resulting in a higher kappa number and viscosity. A lower degradation of hexenuronic acid correlated well with a lower AOX content in the effluents, affirming earlier theories that hexenuronic acid has an important impact on AOX formation.Secondly, this research aimed at studying bleachability in (OO)Q(OP)D(PO). The bleachability was defined as delignifying and brightness gain bleachability, which is suited to ECF light bleaching sequences. The delignifying and brightness gain bleachability were used to evaluate the stages in (OO)Q(OP)D(PO) in regard to the unbleached kappa number. When comparing different stages, it is possible to distinguish the bleaching efficiency in each stage. For this ECF light sequence, the bleachability depends on the purpose of the stage. It was found that in the stages that are mainly delignifying (OO and D), a higher unbleached kappa number is beneficial for the delignifying bleachability, although the brightness gain is not improved. However, in the stages that are mainly brightness increasing (OP and PO), the brightness gain bleachability is improved by a lower unbleached kappa number.Thirdly, the bleaching of the pulp samples in this study with the ECF light sequence was most effective with a kappa number around 32 after cooking. Although an even higher kappa number resulted in a higher yield after cooking, it seemed that this bleaching sequence cannot preserve the yield gain. Kappa number 32 also gave the best results in regard to brightness ceiling and viscosity. On the other hand, kappa number 27 was the most favourable with regard to yellowing and chemical charge.
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| 5. |
- Starrsjö, Sara, et al.
(författare)
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Reduction of adsorbable organically bound halogens (AOX) formation at near-neutral pH chlorine dioxide bleaching of softwood kraft pulp
- 2020
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Ingår i: Holzforschung. - : Walter de Gruyter GmbH. - 0018-3830 .- 1437-434X. ; 74:6, s. 597-604
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Tidskriftsartikel (refereegranskat)abstract
- Recently, a new type of bleaching sequence, Elemental Chlorine Free (ECF) light with one D stage, has been developed. It combines the efficiency and high selectivity of chlorine dioxide (ClO2) bleaching with more environmental friendly oxygen based bleaching chemicals. This work examines the effect of pH on the formation of adsorbable organically bound halogens (AOX) in an intermediate D stage - a single ClO2 stage at the middle of an ECF light bleaching sequence. Carbon dioxide (CO2) is used to generate a bicarbonate buffer in situ, stabilizing the pH during the bleaching. Near-neutral pH is hypothesized to decrease the formation of strongly chlorinating species, so that the AOX formation is reduced. The results indicate that a near-neutral pH D stage can reduce the AOX content in the effluents with up to 30%. The ISO brightness was unchanged to a lower ClO2 consumption. The pulp viscosity was slightly higher after near-neutral pH D stage, but to its disadvantage a lesser delignification and removal of HexA was obtained. The degradation of HexA correlated well with the AOX, affirming earlier theories that HexA has a major impact on the AOX formation. The higher amounts of residual HexA and lignin resulted in more thermal yellowing of the pulps bleached with a near-neutral pH D stage.
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